package ecomm.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import ecomm.entity.User;
import ecomm.mapper.UserMapper;
import ecomm.service.UserService;
import ecomm.util.RedisUtil;
import ecomm.util.TokenUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.DigestUtils;
import org.springframework.util.StringUtils;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;

import java.util.concurrent.TimeUnit;

@Service
@Transactional
public class UserServiceImpl extends ServiceImpl
        <UserMapper, User>
        implements UserService {
    @Autowired
    private RedisUtil redisUtil;
    @Autowired
    TokenUtil tokenUtil;

    @Override
    public Page<User> pageUsers(Integer currentPage, Integer pageSize) {
        Page<User> page = new Page<>(currentPage, pageSize);
        return this.page(page);
    }

    @Override
    public boolean register(User user) {
        // 查重
        if (this.count(new QueryWrapper<User>()
                .eq("username", user.getUsername())) > 0) {
            throw new IllegalArgumentException("用户名已存在，请替换其他用户名");
        }
        if (this.count(new QueryWrapper<User>()
                .eq("email", user.getEmail())) > 0) {
            throw new IllegalArgumentException("邮箱已被注册！");
        }
// 密码加密
        if (user.getPassword() == null) {
            throw new IllegalArgumentException("密码不能为空！");
        }
        user.setPassword(DigestUtils.md5DigestAsHex(user.getPassword().getBytes()));
        user.setStatus(1);
        return this.save(user);
    }

    @Override
    public String login(String username, String password) {
        // 登录验证，验证是否正确输入username、password
        if (StringUtils.isEmpty(username) || StringUtils.isEmpty(password)) {
            throw new IllegalArgumentException("用户名或者密码不能为空！");
        }
        QueryWrapper<User> queryWrapper = new QueryWrapper<>(); // 用于实现查询条件对象
        // 根据用户名、密码查询状态为在用的用户
        queryWrapper.eq("username", username)
                .eq("password", DigestUtils.md5DigestAsHex(password.getBytes()))
                .eq("status", 1);
        User user = this.getOne(queryWrapper);
        if (user == null) {
            throw new IllegalArgumentException("用户名或密码错误，请查证后重新操作！");
        }
        String token = tokenUtil.generateToken();
        // 将生成的token放到Redis缓存中，同时设定有效时长
        redisUtil.set("user:token:" + token, user.getId().toString(), 30, TimeUnit.MINUTES);
        // 建立用户ID与token的映射
        redisUtil.set("user:id" + user.getId(), token, 30, TimeUnit.MINUTES);
        return token;
    }

    @Override
    public User getUserByToken(String token) {
        // 查找Redis缓存中是否有token
        if (!tokenUtil.validateToken(token)) {
            return null;
        }
        // 从Redis中获取token映射的用户ID
        Object userIdObj = redisUtil.get("user:token:" + token);
        if (userIdObj == null) {
            return null;
        }
        try {
            Long userId = Long.valueOf(userIdObj.toString()); // 获取Redis中的UserId
            User user = this.getById(userId); // 查询并返回用户信息
            if (user != null) {
                // 刷新token的有效期
                redisUtil.set("user:token:" + token, user.getId().toString(), 30, TimeUnit.MINUTES);
                redisUtil.set("user:id" + user.getId(), token, 30, TimeUnit.MINUTES);
            }
            return user;
        } catch (Exception e) {
            System.err.println("没有找到与这个token适配的User: " + e.getMessage());
            return null;
        }
    }


    @Override
    public boolean logout(String token) {
        User user = getUserByToken(token);
        if (user != null) {
            // 刷新token值
            redisUtil.delete("user:token:" + token);
            redisUtil.delete("user:id" + user.getId());
            return true;
        }
        return false;
    }
    @Override
    public boolean validateToken(String token) {
        return tokenUtil.validateToken(token);
    }


}

